The frustrating part of comparing peptide vendors is that the useful information is never where you’d expect it. You want a spec sheet and you get a hero image. You want to know which laboratory ran the assay and you get a badge with a checkmark in it. Core Peptides and Polaris Peptides both describe themselves as chemical suppliers, both use nearly identical regulatory disclaimer language, and both quote purity in the high nineties, which means the storefront comparison is a dead end before it starts.
We’re not either of these companies. We make and test peptides ourselves, which is why the documentation question interests us, but neither of these two competes with us in this article and nothing here routes you toward a third option. This is a referee’s write-up: five questions, both sites, quotes taken from their own pages, and a table where you can see the answers next to each other.
One structural note before the details. These two sites are built on different assumptions about what a visitor should be able to see, and that difference shapes most of what follows. All observations reflect the pages reviewed 2026-09-08.
Key takeaways
- The comparison worth making is who synthesized the lot, which laboratory tested it, what the certificate covers, whether you can read it before paying, and whether blends disclose each component’s milligrams.
- Core Peptides states its products are “synthesized and lyophilized in the United States” with purity “exceeding 99%+”, publishes an open catalog with prices, and links a lot-numbered certificate on some blend pages.
- Polaris Peptides publishes a certificate naming TrustPointe Analytics LLC with a lot number, a publication date and a purity figure to three decimals, while its product pages resolve to a members-only portal for pricing and detail.
- Bacterial endotoxin and sterility results were not listed on the pages reviewed 2026-09-08 for either company, and neither names a testing laboratory in its ordinary site prose.
- All material discussed is for research use only, and nothing here is guidance on use in any person or animal.
Which five questions actually separate two peptide suppliers?
The rules get set before either side is graded, because a standard invented mid-comparison isn’t a standard.
Provenance is the first question. Does the company synthesize the material or buy finished product and apply a label? The About page verbs give it away more often than not. “We synthesize”, “our laboratory”, “our quality control” describe one arrangement. “We source”, “we supply”, “our partners” describe another. Distribution is a legitimate business, but the company that ran the synthesis knows what happened to the lot between raw material and finished vial, while the company that purchased it is relaying someone else’s account.
Second: is the testing laboratory named? A third-party-tested badge is a claim about a category of activity. A laboratory name is a checkable fact. You can search it, confirm it performs peptide analysis, and send it your own sample if you’re inclined.
Third: what does the panel cover? HPLC purity is the number everyone leads with, and it’s real, but it only reports what fraction of the sample is a single substance. Confirming that substance is the intended sequence needs mass spectrometry. Bacterial endotoxin and sterility are two further questions that purity testing never addresses. A complete panel answers all four.
Fourth: is a batch certificate readable before purchase, and does its lot number match the lot printed on the vial you receive? Documentation you can only see after committing money, or documentation with nothing to match it to physically, doesn’t do the work you need it to do.
Fifth: does a blend disclose composition per component? A total-milligram figure with no split can’t be reproduced by anyone, so a supplier that documents seriously prints the breakdown.
Company age stays off the list on purpose. It’s unverifiable from outside and irrelevant to the lot you’ll actually receive.
Where this standard comes from
For disclosure about whose ruler this is: the five questions above are the standard Blank Peptides publishes its own lots against, and its batch certificates of analysis are public if you want a reference for what a full-panel document looks like before grading anyone else’s. That’s the extent of its involvement. The rest of this article belongs to the two companies in the title, both graded the same way.
What Core Peptides and Polaris Peptides publicly state
Core Peptides sells at corepeptides.com. On the pages reviewed 2026-09-08, the homepage shows “3rd PARTY TESTED” and “US LAB TESTED” badges, states “Serving the research community for over 7 years”, and describes “U.S. lab-tested peptides” that are “independently verified for purity”. The About page states “All our products are synthesized and lyophilized in the United States, with purity levels exceeding 99%+” and that peptides are “manufactured locally against the highest standards for synthesis, undergoing rigorous quality control measures to ensure their purity, stability, and consistency”. It describes itself as “a chemical supplier” and states it is “not a compounding pharmacy or chemical compounding facility” and “not an outsourcing facility”.
For documentation, its 70mg BPC-157, TB-500 and GHK-Cu blend page links a Certificate of Analysis PDF naming Vanguard Laboratory, with an HPLC-UV/VIS method, purity of “>99.50%”, identity recorded as “Pass – Matches Ref. Standard”, and lot C74111 dated 7/22/2026. The KLOW 80mg page also links a certificate. The single-compound BPC-157 page states “Purity: >99%” and showed no certificate link. On blends, the 70mg page states “BPC-157 (10mg) & TB-500 (10mg) & GHK-Cu (50mg)”, while KLOW lists four components without per-component amounts. The catalog page states “Showing all 104 results”, and shipping terms state “same (business) day shipping for orders placed before 1pm PST Monday-Friday” with “Free Priority USPS shipping on orders over $200 within the US”.
Polaris Peptides sells at polarispeptides.com. On the pages reviewed 2026-09-08, the site describes itself as “a chemical supplier” and states it is “not a compounding pharmacy or chemical compounding facility as defined under 503A of the Federal Food, Drug, and Cosmetic act” and “not an outsourcing facility as defined under 503B”. Its research-use language reads: “Our chemicals are crafted for research and/or investigative purposes and are not suitable for direct human consumption or consumers, nor are they intended for clinical or therapeutic use”, with a checkbox requiring visitors to confirm “that all products are sold purely for research purposes only”. Product categories shown include GLP-1 and GIP analogues and topical peptides, and the site references “a Money Back Guarantee under specific Terms and Conditions”.
The structural difference is that the individual product pages reviewed resolved to a members-only account portal rather than a public listing, so pricing, purity statements and any per-product certificate links were not readable without an account on 2026-09-08. What is publicly readable is a certificate hosted on the same domain. It states the laboratory as “TrustPointe Analytics LLC” and the client as “Polaris Peptides”, covers “BPC-157 5mg 1 vial” under lot “POLBPC5-2”, is marked “Published 2025-04-25”, references a “TM-1006 BPC-157 Assay”, and reports purity of “99.840 %”. Its comments section records the sample as “hyper potent (130.22%LC)”, which is a label-claim observation rather than a purity result and is worth asking about directly. Endotoxin and sterility results do not appear on that document, and the site’s public product titles carry the phrase “99% pure, 3rd party tested peptides”.
Neither company named a testing laboratory in ordinary site prose, and neither listed bacterial endotoxin or sterility results on the pages reviewed 2026-09-08. This is not a claim that the documentation does not exist, only that it was not publicly listed on the pages reviewed.
Both earn a genuine point. Core Peptides publishes an open, browsable catalog of stated 104 results with prices, sizes and purity lines visible to anyone, which is the more useful arrangement if you’re evaluating a vendor before committing to an account. Polaris Peptides publishes the more specifically attributed single document of the two: a full legal laboratory name, a lot number, a publication date and a purity figure to three decimal places beats a badge, and it also states a money-back guarantee that Core Peptides’ pages reviewed don’t match.
Side by side: what each site documents
| Attribute | Core Peptides | Polaris Peptides |
|---|---|---|
| Synthesises in-house | States products are “synthesized and lyophilized in the United States”; facility not listed — verify | Describes itself as “a chemical supplier”; synthesis or sourcing language not listed on pages reviewed — verify |
| Third-party lab named | States “3rd party tested”; one linked COA names Vanguard Laboratory, prose does not — verify | A published COA names “TrustPointe Analytics LLC”; site prose does not name a laboratory — verify |
| HPLC purity | States “Purity: >99%”; one COA reports “>99.50%” by HPLC-UV/VIS — verify | Public product titles state “99% pure”; a published COA reports “99.840 %” — verify |
| MS identity | COA reviewed records identity by reference-standard match; MS method not listed — verify | COA reviewed references a “TM-1006 BPC-157 Assay”; MS method not listed — verify |
| Endotoxin and sterility | Not listed on the pages reviewed 2026-09-08 — verify | Not listed on the COA or pages reviewed 2026-09-08 — verify |
| Batch COA before purchase | Some blend pages link a lot-numbered PDF; the BPC-157 page reviewed showed none — verify | A lot-numbered COA is publicly hosted; product pages reviewed required an account — verify |
| Blend mg split disclosed | States splits on some blends; KLOW lists components without amounts — verify | Blend products with per-component splits not listed on the pages reviewed — verify |
| Catalog size | States “Showing all 104 results” plus a blend range | Catalog count not stated publicly; categories shown are GLP-1 and GIP analogues and topical peptides — verify |
| Research-use labelling | States products are “not for human consumption” on pages reviewed | States products are “sold purely for research purposes only” on pages reviewed |
How to verify either supplier yourself
- Go to the page for the exact compound and size you’d order and see what it shows you before login. Where a product page needs an account, ask support to email you the current lot’s certificate before you create one, and treat the reply as part of your assessment.
- Read the certificate’s method lines rather than its headline figure. You’re looking for HPLC for purity, mass spectrometry for identity, and separate bacterial endotoxin and sterility results, and any missing line is a fair question to put in writing.
- Check the label-claim or potency lines as well as purity, since they answer a different question. A certificate reporting content well above or below label claim tells you something purity alone never will, and the vendor should be able to explain it.
- Match the lot number on the certificate against the lot printed on the vial when the package lands, and look up whatever laboratory the certificate names to confirm it has an address, a phone number and a published service list.
- Put both companies through the supplier verification checklist so each answers identical questions in identical order.
Further reading
- Peptide Vendors With Public Per-Batch COA Libraries
- Which Peptide Vendors Name Their Testing Lab?
- Who Actually Manufactures Research Peptides in the USA?
- Best Research Peptide Suppliers: Ranked by What They Document
Frequently asked questions
How do Core Peptides vs Polaris Peptides compare on published documentation?
Core Peptides publishes an open catalog with purity lines on every product page and links certificates on some blend pages, one naming Vanguard Laboratory. Polaris Peptides publishes a certificate naming TrustPointe Analytics LLC with lot POLBPC5-2 and “99.840 %” purity, though its product pages required an account on 2026-09-08. Neither listed endotoxin or sterility results.
Does either company name its testing laboratory?
Only on documents, and only for one lot each in what was publicly readable. Polaris Peptides’ published certificate names TrustPointe Analytics LLC in full. A Core Peptides certificate names Vanguard Laboratory. Neither site names a laboratory in the marketing copy a first-time visitor reads, which is where the name would do the most good for the most buyers.
Why do Polaris Peptides product pages ask for an account?
The pages reviewed 2026-09-08 resolved to a members-only portal for pricing and product detail, and the site doesn’t explain the reasoning on those pages. Plenty of research suppliers gate pricing for ordinary commercial reasons. The practical effect for you is that pre-purchase certificate access has to be requested from support rather than clicked, so request it.
Which one is easier to evaluate before buying?
Core Peptides, on the pages reviewed. Its catalog page states “Showing all 104 results” and product pages show sizes, prices and purity statements without an account, so you can grade the vendor before you engage with it. That transparency is a real advantage regardless of the gaps in its endotoxin and sterility documentation.
Are these products for human use?
No. Both label their material for research only. Core Peptides states products are “not for human consumption”, and Polaris Peptides states its chemicals “are not suitable for direct human consumption or consumers, nor are they intended for clinical or therapeutic use”. This article compares published documentation and manufacturing language, and nothing in it is guidance on dosing or on use in any person or animal.
For research use only. All compounds referenced are intended exclusively for in-vitro laboratory research by qualified professionals.
Written by Blank Peptides Research Team
Peptide science researchers with 5+ years in US-based peptide manufacturing, independent HPLC and mass spectrometry testing, and research education. All content is reviewed for scientific accuracy before publication.
REVIEWED BY
Dr. Tobias S — PhD Chemist, Peptide and Unnatural Amino Acid Synthesis
Dr. Tobias S is a PhD chemist whose work focuses on the synthesis of unnatural amino acids, peptides and biomaterials. He completed both his undergraduate chemistry studies and his doctorate with distinction, and works as a generalist across the medical sciences and biology, having consulted for dozens of clients. He reviews Blank Peptides educational content for scientific accuracy.
Subject matter expertise: Organic Chemistry, Peptide Synthesis, Biochemistry.
